This is how it works:
Say your mind is a computer, with 2GB of RAM. To clear the RAM at any point, all you need to do is perform a system restart. However, you keep on starting new processes, day after day, not shutting down (and clearing the RAM) once. Eventually, you'll run out of RAM and you won't be able to start any new processes. You'll stop working. Your mind will break down. You'll go mad!

People who don't get to sleep for long periods of time run out of short-term memory; and they go mad! You should see a doctor, he'll prescribe something to sort it out, it could be anything from pills, to a machine that helps you breathe, to hypno-therapy. Good luck!